SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c59b6fe2d6b5548a04dc509398fb63baeedf2ad52b2e29ee20bedecc40bf840b' 
  AND token = 'UtSotWH3bSW99tbbaHyk+U+SwrWI+gJkETelDIiw8fc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}